title: Impact of pharmaceutical underutilization: a study of insurance drug claims data.
abstract: OBJECTIVE
  To operationalize the measurement and interpretation of pharmaceutical underutilization using private insurance medical and drug claims data. This study also examined the relationship between underutilization of pharmaceuticals and patient outcomes.
  
  
  METHODS
  Five definitions of pharmaceutical underutilization were used to identify underutilizers of 14 pharmaceuticals in a population of people aged 55 and over. Definitions 1 to 4 required the calculation of the apparent daily dose of the drug versus a standard dose. Definition 5 identified underutilization by the variation in apparent daily dose. Average monthly health services utilization figures were compared among appropriate utilizers and both moderate and severe pharmaceutical underutilizers for each of the five definitions.
  
  
  RESULTS
  The most consistent results were found using Definition 5, variability in dosage. There were statistically significant (p < 0.05) differences in use of medical services among patients whose use of the pharmaceutical was more variable than other patients taking the same medication.
  
  
  CONCLUSIONS
  Viewing noncompliance from the perspective of stability of consumption rather than the absolute value of the consumption may be a better predictor of increased health services utilization.
authors.affiliation: Mikalix & Company, Waltham, Mass., USA. brookeh@neri.org
authors.forename: B S
authors.initials: BS
authors.lastname: Harrow
authors.forename: B L
authors.initials: BL
authors.lastname: Strom
authors.forename: J A
authors.initials: JA
authors.lastname: Gans
mesh_terms: D000368:Aged; D002908:Chronic Disease / Q000188:drug therapy; D017723:Drug Utilization Review / Q000379:methods*; D005260:Female; D006801:Humans; D007345:Insurance Claim Review; D007356:Insurance, Pharmaceutical Services; D008297:Male; D008875:Middle Aged; D016312:Treatment Refusal; D014481:United States